Adjustable angle drawing guide



April 8, 1969 R. KNIGHT 3,436,833

ADJUSTABLE ANGLE DRAWING GUIDE Filed Jan. ll, 1968 Sheet of 2 FIGA` 954%?.

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ADJUSTABLE ANGLE DRAWING GUIDE I Filed Jan, 11, 1968 sheet 2 J y L4@ sa S l 5 i Rd 75 7@ INVENTOR a 45 44d d 3 Pofer L kwa/f7' United States Patent O 3,436,833 ADJUSTABLE ANGLE DRAWING GUIDE Robert L. Knight, Whittier, Calif. (17372. Koledo Lane, Apt. D., Huntington Beach, Calif. 92647) Filed Jan. 11, 1968, Ser. No. 697,146 Int. Cl. B431 7/06 U.S. Cl. 33-99 10 Claims ABSTRACT OF THE DISCLOSURE Generally speaking, the present invention comprises an adjustable-angle drawing guide which provides a relatively small, compact instrument including a longitudinal main ruler member which has two main straight edge portions, either one of which can be used to guide a drawing instrument in drawing a longitudinal main straight line on a piece of paper or other surface and which can have a swinging ruler arm portion -which normally is in closed, substantially inoperative relationship, pivotally moved into any of a plurality of different desired angular relationships relative to the longitudinal main ruler member so as to make it possible to guide a drawing instrument during the drawing of another or auxiliary line at Va desired angular relationship with respect to a main longitudinal line drawn with the aid of the main longitudinal ruler members guiding edge. In other words, lines may be drawn so as to form any of a plurality of included angles through the use of the instrument as a drawing guide and the lines may be. drawn to various desired lengths in any of said angular relationships. Both the angular relationships and the lengths may be visibly indicated by the provision of angular relationship indicating means and the provision of length measuring indicia or scale means. The ruler arm portion is pivotally attached with respect to the longitudinal main or base ruler member by multiposition detented pivotal mounting means capable of holding the two ruler parts in any of a selected plurality of angular relationships but capable of being forcibly manually overridden to allow angular relative repositioning thereof as desired. The relatively pivotal ruler elements in a preferred form are also provided with end located positioning and locking means adapted to normally maintain the two ruler parts in parallel relationship but capable of being manually controllably relatively disengaged, released, and unlocked to allow the relative pivotal movement of the two ruler portions for the purposes outlined above. The two relatively pivotally movable ruler portions have substantially planar flat bottom surfaces so as to provide for firm, stable, supported contact with respect to an auxiliary underlying horizontal supporting surface, such as a sheet of drawing paper on a drafting table or the like, thus making it possible to accurately use the instrument for drawing various different angularly related line portions in the manner referred to above without the instrument having any instability which might affect the accuracy of such drawing operations.

In one preferred form, the portion of the longitudinal main or base ruler member which normally carries the swinging pivotally mounted ruler arm portion thereunder may be provided with auxiliary, downwardly directed sup- ICC port means capable of firmly supporting same even when the swinging ruler arrn portion is moved away from its normal, underlying position.

With the above points in mind, it is an object of the present invention to provide a novel, adjustable-angle dra-wing guide and instrument having any or all of the advantages referred to herein, and including any or all of the features referred to herein, generically and/or specifically, and individually or in combination, and which is of extremely simple, inexpensive construction, suitable for manufacture as a three-piece or two-piece item wherein the major elements (usually at least the two relatively movable main portions thereof) may be made of extremely inexpensive molded plastic material, although they may be made of stamped or otherwise formed construction and of materials not necessarily limited to plastics, but including metals and various other suitable materials capable of being easily formed to the desired configurations and requiring a minimum of tooling and, therefore, of capital costs and adapted for production at an extremely low cost per unit such as to facilitate widespread and large scale manufacture, sale, and use of the invention for the purposes outlined herein or substantially equivalent purposes.

Further objects are implicit in the detailed description which follows hereinafter (which is to be considered as exemplary of, but not specifically limiting, the present invention), and said objects will be apparent to persons skilled in the art after a careful study of the detailed description which follows hereinafter, and all such implicit objects are intended to be included and comprehended herein as fully as if particularly defined and pointed out herein.

'For the purpose of clarifying the nature of the present invention, two exemplary embodiments of the invention are illustrated in the hereinbelow-described figures of the accompanying drawings and are described in detail hereinafter.

FIG. 1 is a top plan view of one exemplary embodiment of the present invention with the swinging ruler arm portion in closed, parallel, underlying relationship with respect to the longitudinal main or base ruler member.

FIG. 2 is a top plan view similar to FIG. 1, but illustrates the exemplary first form of the invention after the swinging ruler arm portion has been manually effectively unlocked, disengaged and moved from the closed relationship shown in FIG. 1 and pivoted 90 into one particular angle-defining relationship (in this Case a rightangle-defning relationship) with respect to the longitudinal main or base ruler member. Of course, it should be understood that the swinging ruler arm portion can be moved into a number of other different angle-defining relationships (a counterclockwise extreme one of which is shown in phantom in FIG. 2) and that the right angle showing thereof in FIG. 2 is illustrative only.

FIG. 3 is a bottom plan view of the exemplary first embodiment of the invention shown in FIG. 1 in closed form.

FIG. 4 is a bottom plan view of the exemplary first embodiment of the invention shown in FIG. 2 in a selected right-angle-defining one of the plurality of different open relationships.

FIG. 5 is a fragmentary perspective view of the pivotal mounting portion of the longitudinal main 0r base ruler member, with the swinging ruler portion and, in particular, the inner pivotal attachment portion thereof, lbeing fragmentarily shown in perspective positioned in vertically downwardly exploded relationship with respect thereto. In this fragmentary, exploded perspective view an effective interconnecting pivot pin means is also shown in exploded relationship from its normally rotatably interconnected relationship as shown in FIGS. 1 4. This view also shows the multiposition detent means in exploded relationship.

FIG. 6 is an enlarged, fragmentary view taken substantially along the plane indicated by the arrows 6--6 of FIG. 2.

FIG. 7 is an enlarged, fragmentary, partially broken away view taken substantially along the plane indicated by the arrows 7-7 of FIG. l.

FIG. 8 is a fragmentary view illustrating the engagement or disengagement operation by which the positioning and locking means carried by the outer end of the swinging arm ruler portion and the corresponding right end of the longitudinal main or base ruler member are engaged and locked or unlocked and disengaged, respectively.

FIG. 9 is an enlarged, fragmentary, sectional view similar in many respects to FIG. 6, but illustrates a slight modification of the invention wherein a different and effectively integral type of interconnecting pivot pin means is employed.

Generally speaking, the present invention may be said to comprise a longitudinal base ruler member, such as is generally designated -by the reference numeral 20, which has a substantially at top surface 22 (subject to the hereinafter described exceptions), a substantially flat bottom surface 24 (at least along the left half thereof), and a pair of substantially parallel, longitudinal drawing instrument-guiding straight edges such as indicated at 26 and 28, respectively, terminating in a longitudinally spaced pair of substantially parallel end edges which are perpendicular to said longitudinal parallel edges 26 and 28 and which, in the exemplary first form of the invention, comprise a left end edge 30 and a right end edge 32.

It should be noted that the substantially fiat bottom surface 24 of the longitudinal main or base ruler member extends downwardly to a common -bottom contact plane along substantially the entire left half of the length of the main ruler member 20 but is upwardly recessed and cut away along substantially the right half thereof whereby to define a longitudinal ruler arm portion receiving recess, indicated generally at 34, underlying substantially the entire right half of the main ruler member 20 and normally receiving therein a swinging ruler arm portion, indicated generally at 36, and which has a substantially fiat bottom surface 38 substantially coplanar with the flat bottom surface 24 of the left half of the main ruler member 20, thus providing an arrangement capable of resting in a very stable manner upon an underlying supporting surface, such as that indicated at 40, which may comprise a sheet of drafting or drawing paper or the like, resting upon a drafting board or other firm, underlying, horizontal supporting surface means.

An inner end of the swinging ruler arm portion indicated generally at 36 is pivotally attached with respect to the longitudinal main or base ruler member, indicated generally at 20, by pivotal mounting means, one exemplary form of which is generally designated by the reference numeral 42, and which effectively comprises an inner pivotal attachment means or portion 44 in the form of a disc member .designated by said reference numeral 44, and also comprises a pivotal mounting portion indicated generally at 46, intergrally carried substantially centrally at the junction of the right end of the previously mentioned flat bottom surface 24 and the left end of the previously mentioned swinging ruler arm mounting recess 34 and normally receiving and pivotally mounting said discshaped pivotal attachment portion 44 integrally carried by the inner end of the swinging ruler arm portion 36. In the example illustrated, said pivotal mounting portion 46 comprises the effective left end of the previously mentioned ruler mounting recess 34 including a partially arcuate or disc-shaped portion at the extreme left thereof and is generally designated by said reference numeral 46.

In the exemplary first form ofthe invention illustrated,

the pivotal mounting means 42 also includes an effective pivot pin means -48 mounted in aligned upper and lower hole portions `62. and centrally coaxially and relatively rotatably interconnecting said disc-shaped pivotal attachment portion 44 and the pivotal mounting portion 46 of the longitudinal main or base ruler member 20 with the entire swinging ruler arm portion 36 underlying the upwardly recessed and cut-away right half part of the longitudinal main ruler member 20 in a manner such that the two bottom surfaces 24 and 38 are substantially coplanar and effectively form a common bottom contact plane such as is indicated in broken lines at 50 in FIG. 7, adapted to be positioned upon and provide very firm, stable supported contact with an underlying auxiliary support member surface such as that indicated at 40 when the entire device is in closed relationship such as is shown in FIGS. l, 3, and 7.

The pivotal mounting means indicated generally at 42 is effectively provided with multiposition detent means, such as is indicated generally at 52, of a type adapted for forcibly manually overridably resiliently maintaining any one of a plurality of manually selected, relative rotative angular positionings of said swinging ruler arm portion 36 with respect to the longitudinal main or base ruler member 20 whereby to define a desired angular relationship therebetween at either side thereof.

In the exemplary first form of the invention illustrated, the detent means indicated generally at 52 takes the form of a downwardly directed, resiliently defiectable pin 54 carried by the underneath surface of the cut-away, centrally positioned recessed portion of the longitudinal main or base ruler member 20 effectively comprising the previously mentioned pivotal mounting means 46, and also includes a plurality of arcuately spaced, upwardly open cooperable recess means 56 positioned for receiving cooperation with the downwardly directed resilient pin 54 when the swinging ruler arm portion 36 is pivoted relative to the longitudinal main or base ruler member 20.

It will be understood that, in the example illustrated, the recesses 56 are arcuately spaced apart 15 for illustrative purposes only and that this permits the positioning of the swinging ruler arm portion 36 in any of a plurality of 15 displaced positions, thus making possible the position thereof as shown in FIGS. l, 3, and 7 in a 0 displaced position, as shown in solid lines in FIGS. 2 and 4 in a 90 displaced position, in a 120 displaced position as shown in phantom in FIG. 2, or in any other one of the total of seven other possible positions between said 0 and 120 positions, each lying at a different angular 4position in incremental steps of 15.

In other words, the swinging ruler arm portion 36 may be positioned at a 0 position, a 15 displaced position, a 30 displaced position, a 45 displaced position, a 60 displaced position, a displaced position, a 90 displaced position, a displaced position, or a 120 displaced position, and when in any of said positions, the downwardly directed resilient pin 54 may be firmly received within the corresponding one of the nine different recesses 56 and will firmly hold and lock the swinging ruler arm portion 36 in said selected adjusted position thereof relative to the longitudinal main or base ruler member 20.

However, it should be clearly understood that whenever repositioning adjustment of the swinging ruler arm portion 36 with respect to the longitudinal main or base ruler member 20 is desired, it is only necessary to manually apply torque to the outer end of the swinging ruler arm portion 36 around the axis of the pivot pin 48 to an extent such as to override the resiliently deectable engagement of the resilient pin 54 and the corresponding recess 56 to an extent such that the pin S4 will be deected and forced out of the recess 56 and will then arcuately move across the upper surface of the discshaped pivotal attachment portion 44 until it reaches the next recess 56 into which it will immediately resiliently extend in a locking manner. This will, of course, lock the ruler arm portion 36 in said angularly adjusted position with respect to the ruler member 20 unless manual torque is applied in a manner such as to cause further angular repositioning movement of the ruler arm portion 36 until the desired angular relationship is reached.

The deflecting of the resilient pin 54 during the angular readjustment operation just described is facilitated by reason of the provision of a slight vertical space, such as is indicated at 58 in FIGS. 6 and 7, between the upper surface of the disc-shaped pivotal attachment portion 44 and the bottom surface of the pivotal mounting portion 46 of the longitudinal main or base ruler member 20, which is provided by reason of the effective integral washer 60 carried on the upper surface of the pivotal attachment portion 44 immediately around the pivot pin hole `62 It should be noted that the invention is not limited to the directional mounting of the detent means 52 illustrated in the drawings and just described in detail since it is just as feasible to reverse the mounting and directional relationships of the resilient pin S4 and multiple recesses 56 without departing from the broad spirit, scope, and teachings of the present invention, and such arrangements and various other substantial functional equivalents are intended to be included and comprehended herein. This is also true 4with respect to the positioning of the washer 60 which might be carried by the bottom surface of the pivotal mounting portion 46 rather than by the upper surface of the pivotal attachment portion 44 and, in certain forms of the invention, it might be a separate, discrete washer rather than an integral washer.

The `device is further provided with angular relationship indicating means, such as is generally indicated at 64, for visibly indicating in what angularly adjusted relative position the ruler ann portion 36 and the longitudinal main or base ruler member 20 are at any particular moment when the observation is taken. In the exemplary first form of the invention illustrated, the angular relationship indicating means 64 comprises angular scale or indicia means, such as is indicated at 66, of a visible type carried in arcuately spaced positions fby the upper surface of the pivotal attachment portion 44 at positions correlated with the corresponding recesses 56 of the multiposition detent means 52, and further includes viewing window means, such as indicated at 68, carried by an overlying portion of the longitudinal main or base ruler member 20 immediately above the underlying recessed pivotal mounting portion 46 and the :rotating disc-shaped pivotal attachment portion or means 44 and positioned such that a person using the drafting instrument may look directly down through the viewing window means 68 and observe a particular part of the angular indicia or scale means 66 which provides the information specifying the angular position of the ruler arm portion 36 relative to the longitudinal base ruler member (or at least to the right half portion thereof) at that particular instant. In other words, the angle included between the -right-hand half of the drawing instrument guiding straight edge 26 of the main ruler portion and the right-hand drawing instrument guiding straight edge 70 of the swinging ruler arm portion 36 will be that visibly displayed in the viewing window 68.

Of course, it will be understood that the angle included between the left-hand half of the drawing instrument guiding straight edge portion 26 of the longitudinal main or base ruler member 20 and the left-hand drawing nstrument guiding straight edge 72 of the swinging ruler arm portion 36, will be the supplementary angle to that displayed in the viewing window 68, although, if desired, the angular scale or indicia means 66 may be arranged to directly indicate said left included angle Irather than the right included angle. This is a matter of optional choice.

In the exemplary iirst form of the invention illustrated, the pivotal mounting means 42 also includes pivotal movement limiting stop means carried by the bottom of the longitudinal main or base ruler member 20 immediately leftwardly adjacent to the previously -mentioned recessed pivotal mounting portion 46 thereof, and is generally indicated by the reference numeral 74.

In the exemplary lirst form of the invention illustrated, said stop means 74 comprises a downwardly projecting 120 angularly positioned stop shoulder means 76 terminating in a position underlying the straight edge 26 and an oppositely perpendicularly directed stop shoulder means 78 terminating in a position underlying the 0pposite straight edge 28 at substantially the center thereof. This positively limits the pivotal movement of the ruler arm portion 36 to the leftwardly extreme position shown in phantom in FIG. 2 and to a position (not shown) directly opposite to that shown in solid lines in FIG. 2. However, in certain cases, the second-mentioned stop shoulder portion 78 and may not be needed and may be modified or eliminated entirely in the event that it is not intended that the swinging ruler arm portion 36 ever move into an angular position on the opposite side of the fright-hand half of the longitudinal main ruler member 20 from that shown in FIG. 2. In this case, it is also possible to eliminate corresponding portions of the recess means 56 and angular scale or indicia means 66 such as are shown in phantom in FIG. 5 and which correspond to said undesired opposite angular positioning of the swinging ruler arm portion 36.

The swinging ruler arm portion 36 has a free outer end portion, such as is generally designated at 80, which is adapted to be normally locked with respect to the corresponding =right end 32 of the longitudinal main or base member 20 by the provision of positioning and locking means such as is generally designated at 82 and 'which is perhaps best shown in FIG. 8.

In the exemplary tirst for-m of the invention, tioning and locking means 82 takes the form of an upstanding abutment portion 84 carried by the outer free end 80 of the ruler arm portion 36 at a location immediately longitudinally beyond the corresponding right end 32 of the longitudinal main or ibase ruler member 20 when they are in their normal closed and locked relationship as shown in FIGS. 1, 3, and 7. In fact, the upstanding abutment member 84 has a fiat inside contact surface 86 adapted to abut and firmly contact the right end 32 of the longitudinal main or base ruler member 20 when the positioning and locking means 82 is in the closed, locked relationship just mentioned.

The upstanding abutment member 84 has a manually graspable handle member 88 which is normally adapted to be manually grasped so that the entire ruler arm portion 36 can be resiliently disengaged from, released from, and unlocked with respect to the right end 32 of the longitudinal main or base ruler member 20 when arcuate movement of the ruler arm portion 36 is desired. This resilient disengagement is best accomplished by bending the free end 80 of the ruler arm portion 36 downwardly until the inner contact surface 86 of the upwardly extending abutment member 84 has been moved out of abutment with the right end 32 of the longitudinal -main or ibase ruler member 20 in a manner such as is best shown in FIG. 8, after which it may be moved a'rcuately in a counterclockwise direction fro-m a position such as that shown in FIG. l toward a position such as that shown in FIG. 2 and into any of the previously mentioned 15 incremental detented positioning locations thereof.

Conversely, it will readily be understood that, when the ruler arm portion 36 is to lbe moved from any one of its eight different possible open positions into a closed position such as is shown in FIG. 1, an operation substantially the reverse of that just described is performedthat is, the upstanding abutment member 84 carried by the free end 801 of the ruler arm portion '36 is pivoted back toward the closed position and is then resiliently sprung downwardly during the final p'hases of the alignsaid posiment operation and then moved upwardly into end locking abutment with the right end 32 just released.

In one preferred exemplary but not specifically limiting form of the invention such as is illustrated in FIGS. 1-8, the right half portion of the longitudinal main or base ruler member 20 may be provided with downwardly directed support leg means, such as indicated at 95), which may preferably be carried by outwardly extreme end or corner portions 92 of the right end 32 of the longitudinal or main ibase ruler member 20 at positions just clearing the corresponding edges 72 and 70 of the swinging ruler arm portion 36 when it is in the fully closed relationship shown in FIGS. 1, 3, and 7. This is possible because of the fact that the swinging ruler arm portion 36 has a transverse width somewhat less than the transverse width of the corresponding right half portion of the longitudinal main or base ruler member 20, thus permitting the mounting of said downwardly directed support leg means 90 immediately outwardly thereof so that the bottom ends of the support leg means 90 will lie in the previously mentioned common bottom contact plane 50 and will thus at all times support the recessed right half portion of the longitudinal main or base ruler member 20 irrespective of whether or not the swinging ruler arm portion 36 is positioned in the recess 34.

It should be noted that the support leg means 90 does not provide any obstacle to the effective locking and unlocking of the previously mentioned positioning and locking means 82 because of the type of resilient downward defiection embodied therein, as is illustrated in the process of being performed in either direction in FIG. 8, since clearance of the downwardly directed support leg means 90 by the downwardly deliected free outer end 80 of the swinging ruler arm portion 36 can be readily effected during such a disengaging or engaging operation.

Said support leg means 90 may lbe two in number as illustrated or, in certain forms of the invention, only one such support leg means may be provided, and the positioning and/or structure thereof may be modified within the limits of the broad scope hereof.

In the exemplary first form of the invention illustrated, the main ruler member 20 and the swinging ruler arm portion 36 may preferably be made of flexible plastic material which may be formed in any suitable manner and which is preferably of a nontransparent type which may be colored, translucent to a degree such as to limit visibility therethrough, or opaque. This is particularly true with respect to the central region of the device immediately overlying the pivotal mounting means 42 so that only the proper portion of the angular scale or indicia means 66 will be seen through the viewing window means 68. However, if the portion overlying the angular scale or indicia means 66 is properly opaque except for the viewing window, the rest of the device, if desired, may be made of translucent or transparent plastic material so that underlying portions of a drawing can lbe seen through the rest of the device if desired.

Also, it should be noted that, in the preferred iirst exemplary form of the invention illustrated in FIGS. 1-8, a slightly downwardly concave, longitudinal trough 93 is provided along substantially the top center part of the length of the main ruler member 20, and -a similar, slightly downwardly concave, longitudinal trough 95 is provided along substantially the top center part of the length of the swinging pivot arm 36. These are merely to facilitate reception of a draftsmans fingertips when holding the corresponding main ruler member 20 or swinging 'ruler arm portion 36 for either movement or immobilization with respect to an underlying drawing surface. However, these troughs are optional and may be modified or eliminated entirely in certain forms of the invention.

In the exemplary form of the invention illustrated, the upper surfaces 22 of both the longitudinal main or base ruler member 20 and the swinging ruler arm portion 36 are provided with length-measuring or length-indicating indicia or scale means. This is an optional feature and, in the exemplary but nonspecifically-limiting first form of the invention illustrated, said length-measuring or indicating scale means comprises a left-to-rght reading lengthindicating scale and/or indicia means indicated at 94 and a similar right-to-left yreading pair of length-measuring or length-indicating scale and indicia means indicated at 96 and 98, respectively. The scale and indicia lmeans 94 is carried adjacent to the straight edge 26, and the oppositely directed and also upside-down reading scale means 98 is carried adjacent to the opposite edge 28. However, the other scale and indicia means 96, which is also oppositely directed but reads in the same upright manner as the firstmentioned scale and indicia means 94, is carried along the center part of the top surface 22 of the longitudinal main ruler member 20. Thus, virtually all types of lengthmeasuring and/or length-indicating conditions of use are provided for by said three scale and indicia means 94, 96, and 918, carried by the longitudinal main or base ruler member 20.

In the exemplary but nonspecifically-limiting first form of the invention illustrated, an additional length-indicating or length-measuring scale and indicia means is carried by the swinging ruler arm portion 36 as indicated generally at 100. However, it should be clearly understood that all of the scale and indicia means jus-t described, while advantageous for the purposes of the present invention, are not to be construed as specifically limiting the invention to the exact arrangements illustrated and described with respect thereto. The scale and indicia means may be modified substantially and, in certain forms of the invention, all or certain portions thereof may be eliminated if desired.

FIG. 9 illustrates a very slight modification of the previously mentioned pivotal mounting means generally designated by the reference numeral 42 in the first form of the invention and generally designated by the reference numeral 42a in this modification of the invention. Indeed, in this modification, all parts which are structurally or functionally similar to Ithose of the first form of the invention are designated by similar reference numerals, followed by the letter a, however.

It will be noted that the major difference of this modified pivotal mounting means 42a from that shown at 42 of the first form of the invention is the fact that the interconnecting efiective pivo-t pin means 48a is of an integral type formed as a centrally positioned, upward extension of the central part of the lower disc-shaped pivot-al attachment portion or means 44a and replaces the corresponding lower pivot pin hole portion 6-2 of the first form of the invention and extends upwardly through the upper pivot pin hole portion 62a in the central part of the pivotal mounting portion 46a of the longitudinal main ruler member 20a and has an effective enlargement 102 which effectively comprises a -retaining ridge holding the main ruler member 20a and the swinging ruler arm portion 36a together in a relatively pivotally mounted relationship. The retaining enlargement 102 may be of a resilient type adapted to be snapped into place by reason of the resiliency of the plastic material thereof or may be formed by pressure and/or heat after assembly of the two ruler portions.

It should be understood that the figures and the specific description thereof set forth in this application are for the purpose of -illustrating the present invention and are not to be construed as limiting the present invention to the precise and detailed specific structure shown in the figures and specifically described hereinbefore. Rather, the real invention is intended to include substantially equivalent constructions embodying the basic teachings and inventive concept of the present invention.

I claim:

1. An adjustable angle drawing guide comprising: a longitudinal main ruler member having at least one longitudinal drawing instrument-guiding straight edge and end edges at opposite ends thereof, at least one of which is substantially transverse .to said straight edge and effectively comprises a locking abutment end edge, said longitudinal main ruler member being provided between opposite ends thereof with pivotal mounting means and `a swinging ruler arm portion pivotally mounted thereby, said pivotal mounting means including a pivotal mounting portion of said longitudinal main ruler member and an inner pivotal attachment portion carried by an inner end of said swinging ruler arm portion and rotatably interconnected with respect to said pivotal mounting portion by the provision of rotatably interconnecting, effective pivot pin means, said swinging ruler arm portion having a longitudinal portion extending from said pivotal attachment portion and terminating in a free outer end portion normally adapted to be positioned in closed substantially parallel and at least partially area-coextensive relat-ionship with respect to a corresponding part of said longitudinal main ruler member extending between said pivotal mounting portion thereof and said locking abutment end edge thereof, said free outer end portion of said swinging ruler arm portion and said corresponding locking abutment end edge of said longitudinal main ruler member effectively defining and comprising abuttingly cooperable positioning and locking means for holding said free outer end portion `adjacent to and in a predetermined, effectively closed, locked relationship with respect to said locking abutment end edge in a controllably disengageable manner, said inner pivotal attachment portion of said swinging ruler arm portion and said pivotal mounting portion of said longi- `tudinal main ruler member being effectively provided with multiposition detent means for maintaining a manually selected, realtive rotative angular positioning and rela- [tionship of said swinging ruler arm portion with respect to said longitudinal main ruler member and being further provided with visibly perceptible angular relationship indicating means for indicating the magnitude of said maintained angular relationship.

2. A device as defined in claim 1, wherein said angular relationship indicating means comprises angular scale and indicia means and alignable index means taking the form of viewing window means overlying said angular scale and indicia means carried, respectively, by said inner pivotal at-tachment portion of said swinging ruler arm portion and said pivotal mounting portion of said longitudinal main ruler member.

3. A device as defined in said longitudinal main ruler said pivotal mounting portion thereof and said locking abutment end thereof is provided with an underlying `recess adapted to receive said swinging ruler arm portion therein in a manner underlying said corresponding part of said longitudinal main ruler member when said swinging ruler arm portion is in parallel, closed relationship with respect thereto.

4. A device as defined in claim 3, wherein said angular relationship indicating means comprises angular scale and indicia means and alignable index means taking the form of viewing window means overlying said angular scale and indicia means carried, respectively, by said inner pivotal attachment portion of said swinging ruler arm portion and said pivotal mounting portion of said 1ongitudinal main ruler member.

claim 1, wherein said part of member positioned between 5. A device as defined in claim 3, wherein the nonrecessed part of said longitudinal main ruler member has a substantially flat bottom surface, each lying in a common bottom Contact plane.

6. A device as defined in claim 1, wherein said multiposition detent means comprises a resilient pin and a plurality of pin-receiving recesses carried by relatively pivotally movable portions of said pivotal mounting means for forcibly manually overridably .resiliently maintaining any manually selected one of a plurality of relative rotative angular positionings of said swinging ruler arm portion with respect to said longitudinal main ruler member corresponding in number to the number of said pinreceiving recesses.

7. A device as defined in cl-aim 1, wherein said free outer end portion of said swinging ruler arm portion has a vertically directed Iabutment member resiliently deflectably carried by said free outer end portion of said swinging ruler arm portion and adapted to be manually locked and unlocked by manual forcible resilient movement into and out of end abutment with said locking abutment end edge of said longitudinal main ruler member and together therewith comprising said positioning and locking means.

Si. A device as defined in cl-aim 3, including pivotal movement limiting stop means carried by a bottom surface part of said longitudinal main ruler portion adjacent to said pivotal mounting portion thereof and comprising correspondingly angularly positioned, downwardly projecting stop shoulder means positioned in the path of swinging pivotal movement of said ruler arm portion whereby to limit the extent of said swinging pivotal movement thereof to a predetermined angular deviation from its initial parallel closed relationship with respect to said longitudinal main ruler member.

9. A device as defined in claim 5, including downwardly directed support leg means carried by said recessed part of said longitudinal main ruler member and extending downwardly to said common bottom contact plane coplanar with Isaid flat bottom surface of the nonrecessed part of said longitudinal main ruler member and adapted, when said swinging ruler arm portion is in nonparallel, open relationship with respect to said recessed part of said longitudinal main ruler member, to support same on an underlying, auxiliary horizontal support member in a stable manner.

10. A device as defined in claim 1, wherein the upper surfaces of said longitudinal main ruler member and said swinging ruler arm portion are provided along straight edges thereof with length-measuring indicia means, said longitudinal main ruler member and said swinging ruler arm portion being made of iiexible plastic material.

References Cited UNITED STATES PATENTS 1,226,172 5/1917 Benjamin 33-4120 1,477,210 12/1923 Dion 33-117 1,616,457 2/ 1927 McWilliams 33-1'17 1,882,354 10/1932 Celenza 33-117 X HARRY N. HAROIAN, Primary Examiner.

U.S. Cl. X.R. 33 115, 120 

